Switching dead-time control techniques and dynamic phasor analysis for power converters

Abstract

The switching converter is the most important part of the power electronics, and it can be divided in-to the DC converter and AC converter. Both of them, their power efficiency and the dynamic analysis are most important parts to design the converters.

In Chapter 1, The dead-time controls, which is essential required to do switching the power switch, for synchronous buck converter are challenging due to the difficulties in accurate sensing and processing the on/off dead-time errors. For the control of dead-times, an integral feedback control using switched capaci-tors and a fast timing sensing circuit composed of MOSFET differential amplifiers and switched current sources are proposed. Experiments for a 3.3 V input, 1.5 V -0.3A output converter demonstrated 1.3~4.6% efficiency improvement over a wide load current range.

In Chapter 2, a large signal dynamic model of the inductive power transfer system (IPTS) for the on-line electric vehicle (OLEV) is developed using the recently proposed Laplace phasor transform. With the help of this dynamic model, the effect of the output capacitor and load resistance variation on the transient response of the IPTS is analyzed. The maximum pick-up current and output voltage for an abrupt in-rush of the OLEV are examined by both the proposed analysis and simulations, and verified by experiments with good agreement. Thus, it is found that the voltage and current ratings of the pick-up remain relatively con-stant regardless of the load resistance.